When the Commission Sportive Internationale (CSI) announced that the International Championship of Makes for 1968 to 1971 would be run for three-litre Group 6 prototypes, Porsche set out to take advantage of the new ruling with one goal in mind: to win its first overall victory in the 24 Hours of Le Mans.

Under the leadership of Ferdinand Piëch and Helmuth Bott, the Porsche 917 was designed by chief engineer Hans Mezger, who crafted a new 4.5-litre air cooled engine for the project. Many other innovative design features were used to reduce the weight and accommodate a larger engine, such as the tubular frame of the car itself being used to pipe oil to the front cooler.

The initial performance of the 917 at Le Mans in 1969 was not what Porsche had wanted, but this was quickly rectified the following year in the 1970 competition. During testing, the chief engineer of the John Wyer Automotive (JWA) Gulf Team – John Horsman – had spotted a pattern of dead gnats on the bodywork of the car. The tail of the 917 was clean, revealing that the air was not flowing over the tail. As a result, a modification was made that gave the 917 a shorter tail and much needed downforce.

The new model was called the 917KH, the Kurzheck (or “short tail”).

On Saturday June 13th, 1970, JWA entered Le Mans with the 917KH in three different versions of Gulf Oil’s famous livery: sky blue with an orange stripe that ran on the front and underbody for Jo Siffert-Brian Redman (#20), sky blue with an orange stripe for Pedro Rodríguez-Leo Kinnunen (#21) and sky blue body and orange roof for David Hobbs-Mike Hailwood (#22). Considered some of the favourites, they had qualified third (#20), fifth (#21) and 10th (#22), but were forced to retire mid-race, with engine troubles for Rodríguez and Siffert after 4 hours and 12 hours respectively, and an incident for Hailwood 5 hours in.

The race was won by Richard Attwood and Hans Hermann in their Porsche 917KH for the Porsche Salzburg team. Porsche had achieved their overall victory at Le Mans.

At the same time, filming was underway for Steve McQueen’s newest film – Le Mans – which aimed to be the ultimate racing movie about the world’s greatest race. The team behind the film had developed new ways to film cars and been granted permission to set up camera crews to film the 1970 Le Mans competition. Using the footage they had of the actual race, the film was a combination of real-race and choreographed stunt-driver shots to bring McQueen’s vision to life.

Solar Productions, McQueen’s production company, purchased a 917KH (Chassis 917-022) for the film, while Jo Siffert loaned McQueen his own (Chassis 917-024-2), catapulting the car to stardom when the film released in 1971. In the same year, 917-024-2 led the funeral procession upon Jo Siffert’s untimely and unfortunate death, before being sold to a private collector. Following the sale, the car then disappeared for nearly 30 years.

In 2001, the 917-024-2 resurfaced after being discovered in a shed in the French countryside. Almost entirely unchanged from its time in Siffert’s care – with even the original space-saver spare, Firestone fuel cell and Firestone Super Sports GP tires still in place – this was undoubtedly one of the greatest barn finds ever. Following a full restoration courtesy of specialists Graber Sportgarage in Switzerland, the Porsche 917KH was sold at auction in California for a record-breaking $14,080,000 (£10,421,909) on the 18th of August 2017.